Sewing machine



' Dec. 25,1923, 1,478,760

F. A. REECE SEWING MACHINE Original Filed June 14, 1919 2 Sheets-Sheet 1Dec. 25, 1923. 7 1,4783% F. A. REECE SEWING MACHINE Original Filed June14, 1919 2 Sheets-Sheet 2 Patented Dec. 25, 1923.

UNITED STATES PATENT OFFICE.

FRANKLIN A. REECE, OF CHESTNUT HILL, MASSACHUSETTS, ASSIGNOR TO THEREECE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, ACORPORATION OF MAINE.

SEWING MACHINE.

Original application filed June 14, 1919, Serial No. 304,223. Patent No.1,424,851, dated August 8, 1922. Divided and this application filedJanuary 26, 1922. Serial No. 531,996.

To all whom it may concern:

Be it known that I, FRANKLIN A. Brown, a citizen of the United States,residing at Chestnut Hill, county of Middlesex, State of Massachusetts,have invented an Improvement in Sewing Machines, of which the followingdescription, in connection with the accompanying drawing, is aspecification, like characters on the drawing representing like parts.

This invention relates to sewing machines of that type in which theunder thread mechanism is in the form of a rotary hook constructed totake a loop of the upper or needle thread and cast it about a bobbincase containing a bobbin carrying the under thread thereby to interlockthe needle thread loop with the under thread.

In the operation of sewing machines of this type it is important thatthe loop of needle thread should pass freely around the bobbin-casewithout being cut thereby, and it is the object of my present inventionto provide an improved construction which will permit the sewing machineto operate at a very high speed without danger that the loop of needlethread will become caught on any projections or shoulders formed on thebobbin-case while said loop is being cast about the bobbin.

WVhile my invention might be embodied.

in various sewing machines in which the under thread mechanism is in theform of a stationary bobbin and rotary hook, I have herein chosen toillustrate it as it would be applied to a buttonhole sewing machine,such as is shown in my co-pending application Se. No. 280,704, filedMarch 5, 1919, but inasmuch as the invention relates simply to the underthread mechanism, I have not deemed it necessary to show the completebottonhole sewing machine.

In the drawings, Fi 1 is a front view of the underthread mec anism of abuttonhole sewing machine such as illustrated in my co-pendingapplication and having my present improvements applied thereto;

Fig. 2 is a top plan view of Fig. 1;

Fig. 3 is a side view;

Fig. 4 is an enlarged front view of the bobbin-case and rotary hook;

Fig. 5 is a top plan view of Fig. 4.

1 indicates part of the frame of a sewin machine which supports theunder thread mechanism and which is situated beneath the bed plateindicated by the dotted line 2, Fig. 1. carries the upper eye-pointedneedle, said needle being situated above the work and controlling theupper or needle thread. 26 indicates the throat-plate which is carriedby the frame 1 and has the sewing opening 25 therein through which theneedle 4 passes when it makes its penetrating thrust. Since the sewingmachine herein shown is a buttonhole sewing machine, this. throat-plate26 is illustrated as provided with a slit 27 to receive the knife whichcuts the button hole in the goods.

The ,under thread mechanism is of the familiar type which comprises astationary bobbin-case 5 adapted to receive a bobbin holder 6 in whichthe bobbin carrying the under thread is placed. Said bobbin holder isretained on an axial stud extending from the bobbin-case and is lockedthereon by means of the usual spring-pressed locking lever 8. The rotaryhook which takes the loop of needle thread and passes it about thebobbin-case is indicated generally at 9, said hook being carried by ashort shaft 10 jour-' naled in bearings 11 formed on the frame 1. Thisshaft 10 is driven from a driving shaft 14 by means of intermeshinggears 12 and 13 that are fast on the shafts 10 and 14, respectively.Said gears are herein illustrated as two-to-one gears so that the hookwill make two rotations for each rotation of the shaft 14. The shaft 14is connected with the needle-actuating mechanism in any usual way sothat it has one rotation for each reciprocation of the needle and,therefore, the hook will rotate twice for each reciprocation of theneedle, all as shown in my said co-pending application. This hook member9 is provided with the usual finger 15 which is constructed so that asit passes the upper center, it will engage the loop 16 of needle thread,as shown in Fig. 4, and by its rotation will cast said loop about thebobbin-case. The bobbin-case is provided with a recess 17 in its frontface near its upper side in which is loosely received a positioningprojection 18 carried b an arm 19 that is secured to the frame 1. eurpose of this positioning projection 18 1s to hold the bobbin-case fromrotation while the machine is in operation.

3 indicates the needle bar which tion 18.

The parts thus far described are or may be all as usual in sewingmachines of this type and as each loop 16 of needle thread is castaround the bobbin-case one leg of the loop is required to pass betweenthe projection 18 and the walls of the recess 17 It is the object of mypresent invention to provide a construction which will obviate anypossibility of the needle loop becoming caught while passing around theprojection 18 even when the machine is runmng at extremely high speed.

The rotary movement of the hook is anticlockwise, Fig. 4, and thefrictional engagement between the hook and the bobbin-case tends t turnsaid bobbin-case in the same direction and thereby holds the wall 28 ofthe recess 17 against the projection 18, as shown in Fig. 2. Thiscontact between the projection 18 and the wall 28 tends to interferewith the free passage of one leg of the needle loop between said parts,especially when the shuttle is operating at a high speed. To prevent anysuch interference, I have provided novel means which acts on thebobbin-case just as the needle loop is to be passed around theprojection 18 and moves said bobbin-case back slightly so as to open aspace between the projection 18 and the wall 28, thereby allowing theloop of needle thread to freely pass said projection. The bobbin-case isprovided with a projection 29 which is acted on by a finger 30 carriedby a rock-shaft 31, and means are provided for turning the rock-shaft togive the finger a slight downward movement just after the loop of needlethread has passed said projection 29 and before it reaches the projec-The rock shaft 31 is carried in a suitable bearing 61 formed on theframe 1 and has fastathereto at its inner end another arm 32 which isadapted to be engaged by acam 33 that is fast on the shaft 14. Therook-shaft 31 is acted on by a spring 34 which holds the arm 32 inengagement with the cam 33. Said cam 33 has a high portion and a lowportion, the low portion extending sli htly more than half way aroundthe cam. en the arm 32 is in engagement with the low portion of the cam33, as indicated in Fig. 1, said arm 30 will be separated slightl fromthe projection 29, and this is the position of the parts while the loopis being passed around the bobbin-case and until after said loop haspassed the projection 29. The space thus provided between the arm 30 andthe projection 291s sufficient to permit the loop of needle thread tofreely pass the arm 30. After the needle loop has passed said projection29 and arm 30, then the high portion of the cam 33 acts on the arm 32and turns the rock-shaft 31 sli htly thereby moving the arm 30downwardly to a slight extent and during such downward movement the arm30 engages the projection 29 and turns the bobbin-case slightly in aclockwise direction. Such turning -movement is sufficient to separatethe projection 18 from the wall 28 of the notch 17 so that the loop ofneedle threadwill pass freely around theprojection without being caughtthereon.

With this improvement the sewing machine can be run at a very high speedwithout danger of the needle thread being caught on any projections onthe bobbin-case or subjected to any jerky action such as would result ifit had to be drawn around the projection 18 While the latter was incontact with the wall 28 of the recess 17.

This application is a division of my application Se. No. 304,223, filedJune 14, 1919 on which patent No. 1,424,851 dated August 8th, 1922 wasissued.

While -I have illustrated a selected embodiment of the invention, I donot wish to be limited to the constructional features shown,

I claim:

In a sewing machine, the combination with an eye-pointed needle, of anon-rotatable bobbin case, a rotary hook for taking a loop of needlethread and casting it about the bobbin case, said bobbin case having arecess on its front face, a positioning arm.

havin a projection to enter said recess and hold t e bobbin case fromrotation, said bobbin case having a rounded protuberance on its frontface, a driving shaft for rotating the hook, a rock shaft extendingparallel to the driving shaft, a face cam on the driving shaft, an armfast on the rock shaft and enaging said cam, a spring acting on the rockshaft to hold the arm in engagement with the cam, a finger fast on therock shaft and adapted to engage said protuberance, the cam-actuatedmovement of the rock shaft causing the finger to move the bobbin casebackwardly as the thread is drawn over the positioning projection.

In testimony whereof, I have signed my name to this specification.

FRANKLIN A. 'REECE,

